Inflatable packers are actuated with applied pressure through a valve assembly once placed in the desired borehole locations. Once set such devices are exposed to potential changes in borehole temperature and pressure that can affect the performance of the inflatable element against the borehole wall. These changes in well conditions affect the internal pressure in the inflatable element and various designs were proposed that passively responded to changes in internal pressure in the set inflatable element with movable compensating pistons that increased the internal inflatable pressure when pressure increased below the inflatable, for example. The increased borehole pressure moved the compensating piston to reduce the inflatable volume and raise its internal pressure. If the situation reversed, the compensating piston could move in an opposite direction to increase the inflatable volume and reduce the internal pressure. There were also provisions to avoid internal overpressure of the inflatable element by use of pressure relief devices that could change the volume or release some internal pressure in the inflated element. Typical of such passive compensation systems are U.S. Pat. Nos. 6,289,994; 6,164,378; 6,119,775; 5,549,165 and US 20160237775.
The present invention addresses a proactive approach to pressure compensation in the inflated packer. It features a power supply coupled to a pump that can be triggered and a piping network that is configurable to pump fluids into the inflated element or to remove fluid from the inflated element. The pressure in the inflated element and below the element in the borehole can be sensed and those pressures transmitted to a local (downhole) or remote location such as a surface location. Other variables can also be sensed such as borehole temperature. A control module includes transmission capability from the borehole to the remote location of measured variables and a signal receiving capability to execute commands such as reconfiguration of the closed or open fluid system that can add or remove fluid. Alternatively borehole fluid can be screened before being pumped into the inflatable while fluid removed from the inflatable can be pumped directly into the borehole for compensation of the internal pressure in the inflatable responsive to well conditions. Power can come from a battery pack or if otherwise available in the borehole can be used to power the components of the active control system that can adjust the internal pressure in the inflatable per a local downhole algorithm or the needs of surface personnel for well control using the inflatable. The sealing capability is continuously maintained and the internal pressure can be controlled as desired in response to transmitted well conditions or, at the discretion of surface personnel or remote control equipment independently of changing variables at the set inflatable location, making the control system an active control system set apart from the passive designs used in the past. These and other aspects of the present invention will be more readily apparent to those skilled in the art from a review of the description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is to be determined from the appended claims.